## Members

Members whose primary funding is from the CTCP are marked with an asterisk.

## Faculty

Mark Wise (Director)John A. McCone Professor of High Energy PhysicsEmail: wisetheory.caltech.edu Office: 412 Lauritsen I am a theoretical physicist with interests in cosmology, particle physics and nuclear physics. I have worked aspects of inflation including the production of gravitational waves, candidates for dark matter (in particular the axion) and aspects of the gravitational evolution of density perturbations. In particle physics I have contributed to our understanding of the physics of heavy quarks and proposed extensions of the standard model relevant for physics at the weak interaction scale. In the area of nuclear physics I proposed a novel effective field theory expansion relevant for the two nucleon sector that takes into account the large NN scattering S-wave scattering lengths. | |

Sean Carroll*Senior Research AssociateEmail: seancarrollgmail.com Office: 401 Lauritsen I'm interested in a broad spectrum of questions in theoretical physics, including cosmology, field theory, gravitation, quantum mechanics, and statistical mechanics. I've worked on models of dark energy, violations of Lorentz invariance, dark forces, black hole entropy, alternative theories of gravity, CMB anisotropies, topological defects, cosmological magnetic fields, 2D quantum gravity, dynamics of extra dimensions, inflationary cosmology, causality violation, approaches to the multiverse, foundations of quantum mechanics, and the arrow of time.
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Clifford CheungAssistant Professor of PhysicsEmail: clifford.cheungcaltech.edu Office: 432 Lauritsen I am a theoretical physicist interested in particle physics and cosmology, with research interests in inflation, baryogenesis, and especially dark matter. My central focus is on the structure of these theories and their consequences for experiments like dark matter direct detection, cosmic ray physics, CMB, and particle colliders. I have explored a spectrum of dark matter topics, including supersymmetric models, dark sectors, non-thermal mechanisms, and asymmetric dark matter. | |

Philip HopkinsAssistant Professor of Physics Email: phopkinscaltech.edu Office: Cahill I'm interested in a range of topics that link small and large scales in the Universe. In particular, my research has focused on how galaxies form, and how stars and black holes form within those galaxies -- and then, in turn, how "feedback" from those black holes and stars (in the form of jets, radiation, winds, explosions, and more) impacts back on galaxies and successive generations of star and black hole formation. Understanding the rapidly growing body of observations within these fields, and their links to closely related fields like the formation of planets (on relatively small scales) or evolution of large-scale structure (on large ones) is a major challenge for theoretical astrophysics. | |

Hirosi OoguriFred Kavli Professor of Theoretical Physics and MathematicsEmail: ooguritheory.caltech.edu Office: 444 Lauritsen I am a theoretical physicist working on quantum field theory and quantum gravity. He is developing theoretical tools to apply superstring theory to fundamental questions in high energy physics, astrophysics, and cosmology. My research strategy is to discover hidden mathematical structures in quantum field theory and superstring theory and to exploit them to invent new theoretical tools to investigate these theories. In particular, I have developed the topological string theory to compute Feynman diagrams in superstring theory and used it to solve mysterious quantum mechanical properties of black holes. I have also worked on conformal field theories in two dimensions, D-branes in Calabi-Yau manifolds, the AdS/CFT correspondence, and properties of supersymmetric gauge theories and their relations to superstring theory. |

## Postdoctoral Researchers

Francis-Yan Cyr-RacineW.M. Keck Institute for Space Studies Postdoctoral FellowEmail: francis-yan.cyr-racinejpl.nasa.gov Office: JPL 169-236A As a data-driven theoretical cosmologist, my research focuses on unravelling the mystery of the dark sector of the Universe. What particles does it contain? What are their properties? Are there new fundamental interactions? To address these questions, I study the distribution of dark-matter substructures within galactic halos through gravitational lensing. I also use observations of the cosmic microwave background and of the distribution of matter on large cosmological scales to study new physics that could govern the dark sector. On a broader level, I am interested in understanding the origins of the Universe and the fundamental laws that determine its evolution. | |

Roland De PutterCaltech Postdoctoral Scholar at JPLEmail: rdputtercaltech.edu Office: 320 Cahill/169-238 JPL I work on a variety of topics in theoretical and observational cosmology. My main goal is to learn about fundamental physics using cosmological data, such as the cosmic microwave background, weak gravitational lensing and galaxy clustering. My interests include dark energy, cosmological constraints on neutrino mass and on the number of neutrino species, and dark matter. One of my main current interests is the question of how to optimally combine information from weak gravitational lensing and galaxy clustering in order to learn about dark energy, modified gravity and other physics. | |

Koji Ishiwata*Moore Prize Postdoctoral Scholar in Theoretical PhysicsEmail: ishiwatatheory.caltech.edu Office: 415 Lauritsen I am interested in phenomenology and cosmology beyond the standard model of particle physics. My research goal is to study new physics models which explain the problems in the standard model, e.g. the hierarchy problem, dark matter, baryon asymmetry of the universe etc., based on experiments and observations. | |

Stefan LeichenauerJohn A. McCone Prize Postdoctoral Fellow in Theoretical PhysicsEmail: sleichentheory.caltech.edu Office: 419 Lauritsen My research is mainly in the areas of theoretical cosmology and quantum gravity. I have worked on the problems of eternal inflation and the multiverse, as well as understanding the holographic nature of the AdS/CFT correspondence. Other research interests include the CMB, effective field theories, and quantum field theory in general. | |

Alvise RaccanelliCaltech Postdoctoral Scholar at JPLEmail: alvisecaltech.edu Office: 346 Cahill My research is mainly focused on the large scale structure of the universe, and how it can be used to better understand the fundamental laws of nature. In particular I use observations of the clustering of structures across cosmic time to test cosmological models and theories of gravity on very large scales. My main current interests include redshift-space distortions, BAO and the ISW effect. I am part of the Prime Focus Spectrograph (PFS). I also am a member of the LOFAR and ASKAP Radio Surveys, and I am interested in studying how we can use forthcoming radio surveys for cosmology, in particular for possibly detecting modified gravity and primordial non-Gaussianity. | |

David Sanford*Moore Prize Postdoctoral Scholar in Theoretical PhysicsEmail: dsanfordcaltech.edu Office: 405 Lauritsen I am interested in phenomenology of physics beyond the standard model of particle physics, with a focus on supersymmetry and dark matter. I am interested in the constraints current and near future dark matter experiments can place on new physics models, and on the intersection of collider and dark matter results in such models. | |

Jennifer Siegal-GaskinsEinstein Postdoctoral Fellow in Theoretical AstrophysicsEmail: jsgtapir.caltech.edu Office: Cahill The identity of the dark matter particle remains one of the most compelling open questions in both cosmology and particle physics. My research focuses on revealing the properties of dark matter using observational probes such as gamma rays and other high-energy particles, and on understanding the origin of high-energy diffuse backgrounds in order to constrain the properties of possible contributing sources, both astrophysical and exotic. I'm also an Affiliated Scientist in the Fermi Large Area Telescope (LAT) collaboration. |

## Students

Jonathan ArnoldGraduate StudentEmail: jarnoldtheory.caltech.edu Office: 410 Lauritsen I am interested in high energy particle physics. My research has focused mainly on dark matter in extensions of the MSSM, the vacuum structure of the standard model, and especially the phenomenology of extensions of the standard model involving heavy colored particles. | |

Kimberly Boddy*Graduate studentEmail: kboddytheory.caltech.edu Office: 409 Lauritsen My area of research is theoretical particle cosmology. Topics that I am interested in include the particle nature of dark matter, baryogenesis, black holes and Hawking radiation, and general aspects of quantum field theories. | |

Bartosz FornalGraduate StudentEmail: fornaltheory.caltech.edu Office: 410 Downs I am interested in a wide range of topics in theoretical high energy physics, astroparticle physics and cosmology. The most extensive project I worked on concerned the lower-dimensional vacuum structure of the standard model. My research includes also constructing and analyzing models beyond the standard model which address the most relevant open issues in particle physics, with a special emphasis on dark matter. | |

Jason PollackGraduate StudentEmail: jpollacktheory.caltech.edu Office: 457 Lauritsen I am interested in the intersection of cosmology, the study of the universe on the largest scales, with particle physics and field theory, the study of the universe on the smallest. My current work involves application of techniques from effective field theory to compute cosmological observables. Past work has involved the cyclic/ekpyrotic model of cosmology and the effects of non-standard models of dark matter on structure formation. | |

Grant RemmenGraduate Student, Hertz Graduate Fellow/NSF Graduate Research FellowEmail: gremmentheory.caltech.edu Office: 453 Lauritsen My fields of study are theoretical high energy physics, theoretical astrophysics, cosmology, and general relativity. My spectrum of interests includes fundamental outstanding problems involving dark matter and dark energy, quantum gravity, black holes, and more. Current work includes quantum field theory around extremal black holes and inflationary cosmology. Previous work has included general relativistic three-body dynamics, HST spectroscopy of Eta Carinae, and galactic dark matter. |